Path: chuka.playstation.co.uk!news
From: mark.henkelis@virgin.net (Mark Henkelis)
Newsgroups: scee.yaroze.programming.3d_graphics
Subject: 3D Lines
Date: Mon, 23 Nov 1998 01:36:14 GMT
Organization: PlayStation Net Yaroze (SCEE)
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Message-ID: <3658b5a3.6585258@news.playstation.co.uk>
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Can anyone tell me where I'm going wrong. I must be missing something
but I can't see it.

I've been trying to display a wireframe of a TMD (actually a box
surrounding a TMD). I can calculate the WORLD values of the vertices
of the box. I then obtain the local/screen matrix and use it to
convert the vertices to screen coordinates, followed by a perspective
transform using the projection distance (i.e. the same algorithm
posted by Stuart and outlined in James' mini tutorial).

However, when I draw lines between the vertices they are translated
from the original position. The only way I can get the wireframe in
the same position as the original TMD is if I set the reference point
to (0,0,0) (I'm using view point/reference point with
GsSetRefView2()). It appears that the LS matrix I obtain doesn't allow
for the reference point, but that doesn't seem likely.

I've checked out the vertex values I calculate initially by
dynamically updating a simple box TMD, which displays exactly where
the original TMD was.

Any ideas?

Thanks, Mark.